Combustion apparatus for liquid fuel and combustion wick

ABSTRACT

As regards size reduction of a burner that draws up liquid fuel to be burned utilizing capillarity, a wick and an igniter are brought into proximity without causing contact with the flame, either a flame-producing section (61) of the wick (6) being constituted in a tapered shape at the tip portion or the tip portion of a wick holder (77) being formed to differ in height in the circumferential direction.

TECHNICAL FIELD

This invention relates to a wick that draws up to be burned a liquidfuel in a lighter or other liquid fuel burner using an alcohol fuel orthe like and to a liquid fuel burner equipped with the wick.

In particular, this invention relates to a wick and a wick peripheralstructure for obtaining a desired burning state in a burner (e.g., acigarette lighter, torch, lantern or other such fire-lighting device,lamp or the like) using a liquid fuel such as an alcohol, a benzenehydrocarbon or a petroleum hydrocarbon.

BACKGROUND TECHNOLOGY

An alcohol fuel such as ethyl alcohol, a benzene fuel of the petroleumbenzene type or a liquid gas fuel such as butane gas or propane gas isgenerally used as the fuel of a cigarette lighter, fire-lighting device,torch, lamp or other such burner.

The performance, ease of use, and structural design of such burnersdiffers depending on the kind of fuel used, and each has its owncharacteristics. In the case of a liquid gas fuel, for instance, the gaspressure is high in the use temperature range of the burner and thevessel storing the fuel has to have a pressure-resistant structure.Moreover, the flame length changes with variation in the gas pressureand since it is a characteristic of the gas pressure to varylogarithmically and greatly with temperature, large change in flamelength with temperature becomes a particular problem. In order to reducethis flame-length variation, the fuel supply mechanism of the burnerrequires a special design countermeasure for affecting temperaturecompensation, which complicates the structure and is disadvantageousfrom the aspect of cost.

In contrast, since a liquid fuel such as an alcohol fuel is a liquid atordinary temperatures and is also relatively low in vapor pressure, itdoes not require a pressure-resistant vessel in the fuel storage sectionand, as such, simplifies the structure of the burner and is advantageousfrom the aspect of cost. Further, in the liquid fuel burner, the meansused to supply the liquid fuel from the fuel storage section to theflame-producing section is generally a wick that utilizes the surfacetension of the liquid fuel to draw it up through continuous fine holesor fine voids among bundled fibers by capillarity and burns it at thetip portion thereof.

Specifically, the wick used for drawing up the fuel is a string-like oneobtained by twisting fibers, one obtained by bundling fibers, one usingboth of these with the glass fibers enclosed in cotton yarn and theresult interwoven with fine metal wires to prevent disintegration, orthe like, whose the lower end portion functions to draw up fuel to beburned at the upper end tip portion.

The flame-producing section of the wick has to be sealed by anopenable/closeable closure cap in order to prevent evaporation of theliquid fuel during nonuse. In addition, a striker wheel or other ignitermust be installed near the wick for scattering sparks to light the wick.

Since the closure cap is ordinarily installed to open and close about apivot at one end portion thereof, its cap portion for sealing theflame-producing section of the wick passes along an arcuate path and,therefore, when it is attempted to make such a lighter or other burnercompact, the need to prevent interference of this path with the wick tipportion, the wick holder, the striker wheel etc. hinders the sizereduction.

Particularly, as regards sealing of the portion of the wick holder ofthe wick, the sealing end portion of the closure cap must interposebetween the wick holder portion and the igniter, e.g., striker wheel, inorder to enable covering of the peripheral portion of the wick holderportion, and if the igniter is spaced away from the wick in order toavoid interference of the sealing end portion with the igniter, aproblem of igniting performance degradation may arise because of, forexample, the elongated spark travel distance. Good igniting performanceis therefore preferably secured by disposing the igniter near the wick.

On the other hand, when the igniter is installed closer to the wick, theflow of air around the flame changes to impede inflow of secondary airto the flame in proportion as the igniter is disposed nearer the flameand the flame tends to swell toward the igniter side so that its edgeportion comes near or in contact therewith. The temperature of theigniter (e.g., striker wheel) is therefore liable to rise. When thestriker wheel is heated, the heat may, for example, be conducted to itsplastic support portion to melt the support portion. The striker wheelmay then be detached by the pressing force of the flint urged againstthe striker wheel, making it useless.

In addition, when a wick made by merely bundling glass fibers or otherfiber material is used and the glass fiber bundle at the tip portion ofthe wick are undone and spread out by contact of the end portion of theclosure cap with the wick tip or contact of the object to be lit (e.g.,cigarette) with the wick tip, the flame thickens, as shown in FIG. 8 tobe explained later, to possibly approach the igniter (e.g., strikerwheel) and, at the same time, the sealing portion of the closure cap isliable to catch a portion of the frayed wick tip and be degraded inevaporation preventing performance.

In consideration of the foregoing circumstances, this invention aims toprovide a wick for a liquid fuel burner that by changing the shape ofthe flame-producing section enables the igniter to be located near thewick while avoiding interference with the closure cap.

The invention further aims to provide a liquid fuel burner which bychanging the shape of the wick holder enables the igniter to be disposedat a position near the wick to ensure good igniting performance, whileavoiding interference with the closure cap, and also avoids elevatedtemperature states by preventing swelling of the flame toward theigniter side.

DISCLOSURE OF THE INVENTION

The invention liquid fuel burner wick, which overcomes the problems setout in the foregoing, is characterized in that, as regards drawing up bythe capillarity of a draw-up section liquid fuel to be burned at aflame-producing section, the flame-producing section is constituted in ashape to have a tapered tip portion.

Where the closure cap is constituted to open and close about a pivot atone end portion thereof, the tip portion of the flame-producing sectionon the side opposite from the pivot of the closure cap is removed toprovide a tapered tip portion.

Where the flame-producing section is composed of glass fibers, its tipportion is preferably fusion-bonded into a pointed shape like the tip ofa writing brush. This wick can be shaped by bundling glass fibers,heating and fusing a portion thereof with a high-temperature burner anddrawing out and separating the fused portion.

On the other hand, the wick can be one with a flame-producing sectioncomposed of a porous glass material having continuous bubbles or asintered porous ceramic material and constituted in a tapered shape.

The wick can be one whose flame-producing section and draw-up sectionare formed of different materials or otherwise be one whoseflame-producing section and draw-up section are integrally formed of thesame material.

As the liquid fuel there can be used an alcohol fuel, for example, onehaving a lower monovalent alcohol, namely, methyl alcohol, ethyl alcoholor propyl alcohol, as its main component and having mixed therewith asaturated hydrocarbon such as hexane or heptane for coloring the flame,or, otherwise, a benzene hydrocarbon or a petroleum hydrocarbon or thelike.

According to the aforesaid wick, since interference with the closure capis avoided by the formation of the tip portion of the flame-producingsection in a tapered shape, the spacing at which the closure cap and thewick are installed can be reduced, the spacing at which the wick and theigniter are installed can also be reduced and, moreover, the closure capcan be formed smaller, whereby design freedom increases and it becomespossible to realize a smaller burner, lower cost and other advantages.

Where the tip portion of a flame-producing section made of glass fibersis fusion-bonded or where a flame-producing section composed of a porousglass material or porous ceramic material is given a tapered shape, thetip portion of the wick does not fray or experience other deformationeven if a cap portion contacts the wick tip portion when the closure capfor preventing evaporation is placed over the wick or if a cigarette orother object to be lit contacts it. Since the shape of the wicktherefore does not change even with repeated use over a long timeperiod, a flame of stable shape can be maintained, temperature rise ofcomponents near the flame can be preclude since the flame does notapproach or contact them, and a good sealed state of the closure cap canbe secured with no wick portion being caught in the gap thereof duringopening and closing. Particularly where the flame-producing section ofthe wick is formed by heating and fusing bundled glass fibers anddrawing out the fused portion, it can be easily fusion-bonded andprovided in a good shape.

The liquid fuel burner of the invention comprises a wick for drawing upby the capillarity of a draw-up section liquid fuel to be burned at aflame-producing section, an igniter for igniting the flame-producingsection of the wick and a closure cap for preventing evaporation capableof sealing the flame-producing section of the wick openably and closablyand is characterized in that a wick holder for holding the wick isprovided around the flame-producing section at a tip of the wick and atip portion of the wick holder is formed to differ in height in acircumferential direction, a tip portion of high height being disposedto be interposed between the flame-producing section of the wick and theigniter.

Preferably the closure cap is constituted to open and close about apivot at one end portion thereof and an edge portion of a sealingportion thereof for sealing the flame-producing section of the wick isformed to differ in height in a circumferential directioncomplementarily to the shape of the tip portion of the wick holder.

As the wick held in the wick holder of the aforesaid type there can beused one whose flame-producing section and drawup section are formed ofdifferent materials or, otherwise, one whose flame-producing section anddraw-up section are integrally formed of the same material.

The structure for forming the tip portion of the wick holder to differin height in the circumferential direction can, as in embodimentsexplained later, be one where the tip of the wick holder is formed withan inclined surface or otherwise can be one where the tip portion of thewick holder is formed steplike.

According to the aforesaid burner, since the tip portion of the wickholder for holding the wick is formed to differ in height in thecircumferential direction and a portion of high height is disposed to beinterposed between the wick and the igniter, the center position of theflame during burning by the wick held by this wick holder is displacedfrom the center of the wick in the direction of moving away to theopposite side from the igniter, thereby enabling the igniter (e.g.,striker wheel) to be disposed near the wick. Moreover, since theaforesaid configuration of the wick holder enables the closure cap to beformed smaller, the igniter can be installed nearer the wick to ensuregood igniting performance while avoiding interference with the closurecap and preventing temperature increase, and, further enhancing designfreedom and realizing size and cost reduction.

Where the shape of the tip portion of the sealing portion of the closurecap is formed to differ in height in the circumferential directioncomplementarily to the shape of the tip portion of the wick holder, theinner diameter, height and other dimensions of the tight sealingstructure for preventing evaporation from the wick can be made smaller,which contributes to size reduction because the path of theopening/closing operation becomes short and the igniter can be closelydisposed.

Where the wick held by the wick holder of the foregoing type is of ashape removed of the tip portion of the flame-producing section on theside opposite the pivot in open/close operation of the closure cap, e.g,where the tip portion of a wick made of glass fibers is fusion-bondedinto a pointed shape like the tip of a writing brush or where it isformed by sintering, interference with the opening/closing of theclosure cap is further avoided and the closure cap can be made small.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic sectional view of a lighter as an example of aliquid fuel burner incorporating a wick that is a first embodiment ofthe invention.

FIG. 2 is a schematic sectional view of a lighter as an example of aliquid fuel burner incorporating a wick that is a second embodiment ofthe invention.

FIG. 3 is schematic sectional view of a lighter incorporating a wickthat is a third embodiment of the invention.

FIG. 4 is schematic sectional view of a lighter incorporating a wickthat is a fourth embodiment of the invention.

FIGS. 5(A)-5(F) show sectional views of the essential portions ofexamples of structures for wick sealing by the closure cap according afifth embodiment of the invention.

FIGS. 6(A)-6(F) show sectional views of the essential portions ofexamples of wick holding structures and structures for attachment of thewick to a top cover according a sixth embodiment of the invention.

FIGS. 7(A)-7(C) views for explaining a step of fusion-bonding the tipportion of the wick made of glass fibers in the first embodiment.

FIG. 8 is a schematic sectional view showing how flame shape changes ina lighter that is a comparative example in test 1.

FIG. 9 is a schematic sectional view of a lighter as an example of aliquid fuel burner that is a seventh embodiment of the invention.

FIG. 10 is a schematic sectional view of a lighter that is an eighthembodiment of the invention.

FIG. 11 is a schematic sectional view of a lighter that is a ninthembodiment of the invention.

FIG. 12 is a schematic sectional view of a lighter that is a tenthembodiment of the invention.

FIG. 13 is a schematic sectional view of a lighter that is an eleventhembodiment of the invention.

FIGS. 14(A)-14(F) show sectional views of the essential portions ofexamples of structures for wick sealing by the closure cap according atwelfth embodiment of the invention.

FIGS. 15(A)-15(F) show sectional views of the essential portions ofexamples of wick holding structures and structures for attachment of thewick to a top cover according a thirteenth embodiment of the invention.

FIG. 16 is a schematic sectional view showing another example of thewick of the seventh embodiment.

FIG. 17(A) shows a metal plate near a flame produced by a lighteraccording to the invention.

FIG. 17(B) is graph showing the results of a test 2 when the change inflame shape caused by placing a metal plate near the wick of aninvention lighter was measured.

FIG. 18 shows a metal plate placed near a wick of a conventionalcomparative lighter.

FIG. 18(B) a graph showing other results of the test 2 when the changein flame shape caused by placing a metal plate near the wick ofcomparative lighter was measured.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the liquid fuel burner and the wick thereof according tothe invention will be explained in the following with reference to thedrawings.

<First Embodiment>

FIG. 1 shows the general sectional structure of a lighter as an exampleof a liquid fuel burner incorporating a wick according to thisembodiment of the invention.

A wick 6 is formed separately of different materials at an upperflame-producing section 61 and a lower draw-up section 62 and the twoare joined by a wick holder 7 with the lower end portion of theflame-producing section 61 and the upper end portion of the draw-upsection 62 in a contacted state.

The flame-producing section 61 is made from glass fibers by, forexample, bundling the glass fibers and fusion-bonding the tip portion61a to form it into a pointed shape like the tip of a writing brush.

In the formation, as illustrated in FIG. 7, glass fiber filaments F arecylindrically bundled to the required diameter like a string and themiddle portion of the fiber bundle is heated with a high-temperatureburner G, as shown in (A). Then, as shown in (B), the opposite ends ofthe glass fiber bundle are drawn outward as the heated portion of theglass fiber filaments F is melted. By this the molten portion of theglass fibers fuse and bind together and the tip portions are drawn toform a point like the tip of a writing brush. Further, as shown in (C),a base 61b is cut, obliquely for example, at a prescribed length,thereby fabricating the flame-producing section 61 of the wick 6 so asto have the bonded tip portion 61a.

The base portion of this flame-producing section 61 is inserted andfixed in the cylindrical wick holder 7 made of metal. The draw-upsection 62, formed as a rod having a large-diameter head portion 62a bymolding and sintering polyethylene powder, is inserted leg portion firstinto a fuel tank 2 through a mounting hole in a top cover 4, the lowerend of the head portion 62a of the draw-up section 62 is held by aretaining portion at the lower end of the hole of the top cover 4, and afastening thread 7a on the outer periphery of the wick holder 7 isscrewed into a threaded hole 4a from above to sandwich an O-ring 18,thereby attaching the flame-producing section 61 to the top cover 4while joining it with the draw-up section 62.

The amount of fuel consumed by the wick 6 when lit, the flame shape andthe flame length are determined by the thickness, number and length ofthe glass fibers of the flame-producing section 61. In contrast, theformation pattern of the gaps in the draw-up section 62, whichdetermines the fuel draw-up and supply characteristics, differs with thethickness, the particle diameter of the sintered polyethylene, thesintered density and the like of the draw-up section 62. The headportion 62a of the draw-up section 62, being formed to a large diameterto have a large volume, constitutes a fuel reservoir for holding theliquid fuel. Burning stabilization is obtained by this fuel reservoir.

In the case of, for example, a cigarette lighter incorporating the wick6, a flame-producing section 61 having a glass fiber thickness of 6 μm,a fiber density (metsuke amount) of 150 mg/cm³, an outer diameter of 3mm and a length of 10 mm is inserted into the wick holder 7 to protrudeto a length of 3 mm from the tip portion of the wick holder 7. On theother hand, the draw-up section 62 is obtained by placing in a moldpolyethylene powder that is a mixture of particles of 70-200 mesh withan average particle size of 140 mesh and sintering it for 10 minutes at170° C. The head portion 62a is formed to an outer diameter of 4.2 mmand a length of 3 mm and the lower leg portion to an outer diameter of 4mm and a length of 37 mm.

This wick 6 is incorporated into the lighter 1, as the burner, with thedraw-up section 62 inserted into a fuel reservoir section 5 to draw upand supply liquid fuel to the flame-producing section 61 and effectsburning at the tip portion 61a of the flame-producing section 61 uponbeing lit by an igniter 10. When continuous burning is effecteduninterrupted, the flame of the burning at the flame-producing section61 is maintained without changing in shape or length by establishing acharacteristic whereby the amount of fuel supplied by the draw-upsection 62 is equal to or greater than the amount of fuel consumption ofthe flame-producing section 61.

The structure of the lighter 1 will be explained next. The lighter 1 hasthe tank 2 of cylindrical shape with closed bottom. Fiber material 3(stuffing) is inserted into the interior of the fuel tank 2 and the topcover 4 is fixed to the upper portion of the tank 2 to constitute thefuel reservoir section 5 for storing liquid fuel.

The tank 2 is, for example, provided as a shaped article made ofpolypropylene with an inner volume of 5 cm³. The fiber material 3 ispolypropylene fiber of a thickness of 1-2 denier compacted in the tank 2to a density of 0.1 g/cm³. 4 g of liquid fuel, a mixture of 95 wt %ethyl alcohol and 5 wt % n-hexane, is poured and impregnated into thisfiber material 3 for storage therein.

The wick 6 is inserted to pass through the middle of the top cover 4vertically into the tank 2 and the wick holder 7 portion is fixed to thetop cover 4. The lower end portion of the draw-up section 62 of the wick6 contacts the fiber material 3 in the tank 2 and draws up the liquidfuel impregnated in the fiber material 3 utilizing capillarity. Theflame-producing section 61 of the wick 6 is lit to burn and generate aflame, and the amount of protrusion of the flame-producing section 61from the wick holder 7 is adjusted to about 3 mm, as mentioned earlier,to obtain a flame length of 30 mm.

The igniter 10 is installed on the top cover 4 to face the tip of theflame-producing section 61 of the wick 6. A bracket 11 of the igniter 10fixed to the top cover 4 has a flint 12 inserted therein to bevertically movable and a rotating striker wheel 13 is provided on theupper end of the bracket 11 as the proximate member nearest to the flameH. The tip of the flint 12 is pressed onto the peripheral surface of therotating striker wheel 13 by the energizing force of a flint pusherspring 14 and rotation of the rotating striker wheel 13 causes sparks tofly toward the wick 6.

A closure cap 16 for evaporation prevention is provided toopenably/closably cover the flame-producing section 61 of the wick 6together with the protruding portion of the wick holder 7. This closurecap 16 is rotatably pivoted by a pin 17 at one end portion of the uppersurface of the top cover 4 of the tank 2. An O-ring 19 is attached tothe outer peripheral root portion of the wick holder 7 and the innerperipheral surface of the sealing portion of the closure cap 16 pressesthereon to enhance the sealing property.

In the assembled state of the lighter 1, the upper end of theflame-producing section 61 of the wick 6 is 2.5 mm higher than theheight of the contact point of the rotating striker wheel 13 and theflint 12, and the positional relationship is set so that the distancebetween the center of the wick 6 and the center of the rotating strikerwheel 13 is 10 mm.

As regards the shape of the flame H during burning, under conditions setto make the flame length 30 mm, the flame width is 9 mm and the positionof greatest flame width is 3 mm from the lower end of the flame and thisflame H burns without touching the rotating striker wheel 13 that is theigniter 10.

In the lighter 1 of the foregoing embodiment, the fact that the tipportion 61a of the flame-producing section 61 of the wick 6 is formed tobe thin shortens the turning radius of the arc of the closure cap 16relative the support point 17 (pin) that does not bring it into contactwith the tip of the wick 6 or the wick holder 7. Accordingly, thedistance between the pivot point of the closure cap 16 and the wick 6can be reduced and, more over sealine the inner diameter of the sealingportion of the closure cap 16 need not be expanded greatly relative tothe outer diameter of the wick holder 7, the closure cap 16 and thelighter 1 can be made small in size.

In other words, the pivot position of the closure cap 16 has to be setso that during opening/closing operation thereof the inner surface ofthe closure cap 16 does not hit the tip of the wick 6 or the tip of thewick holder 7. If the wick tip portion 61a is not made thin, e.g., in alighter using a wick made of glass fibers in a unbonded state, thedistance between the pivot of the closure cap 16 and the center of thewick 6 has to be set relatively long to establish a large turningradius, making the closure cap 16 and the overall structure of thelighter large (see FIG. 8). If it is only desired to make the distancebetween the pivot and the wick 6 short, this is possible by making theinner diameter of the sealing portion of the closure cap 16 large butthe closure cap 16 then comes to rotate at a position apart from theouter diameter of the wick holder 7 so that the distance between thewick 6 and the rotating striker wheel 13 must be made long to avoidinterference with the rotating striker wheel 13. The invention, however,enables size reduction on these points.

<Second Embodiment>

As shown in FIG. 2, the wick 6 of the lighter 1 of this embodiment isformed of a different material from that of the first embodiment.

The flame-producing section 63 of the wick 6 of this embodiment is aporous ceramic sintered body formed in round rod-like shape, containscontinuous bubbles (capillary passages) inside, and is formed thin atthe tip portion. The upper portion of this flame-producing section 63 ismounted to protrude from the tip of the wick holder 7 by a prescribedamount (3 mm). This protrusion amount, the diameter and the likedetermine the size of the flame H. For instance, it is constituted tohave an outer diameter of 3.0 mm and a length of 10 mm.

On the other hand, the draw-up section 62 whose tip portion abuts on thelower end portion of the flame-producing section 63 is again a porousmaterial made of a sintered body of polyethylene powder and formed intoround rod-like shape. An engagement groove 63c is provided in the upperouter periphery of the flame-producing section 63 and a projection 7bdirected toward the center of the upper end portion of the wick holder 7is engaged in and retained by the engagement groove 63c. The lower endportion of the flame-producing section 63 is unitarily joined with theupper end portion of the draw-up section 62 by screwing theflame-producing section 63 and the wick holder 7 into the top cover 4.

The closure cap 16 for sealing the wick 6 and the protruding portion ofthe wick holder 7 has a seal member 20 attached to the tip portion ofits sealing portion. This seal member 20 is constituted so as to pressonto the top cover 4 around the wick holder 7 and establish sealing atthe time of the closing operation of the closure cap 16. The otherportions are formed like those of the first embodiment. The sameconstituent components are assigned the same references symbols andexplanation thereof is omitted.

<Third Embodiment>

As shown in FIG. 3, only the shape of the tip portion of the wick 6 ofthe lighter 1 of this embodiment differs from the second embodiment andother aspects are identically structured.

The flame-producing section 63 of the wick 6 is formed in a rod-likeshape of a porous ceramic sintered body and its tip portion is removedslantedly (a curved surface is also acceptable) at the side portionopposite from the support pin 17 of the closure cap 16. By this,interference of the flame-producing section 63 with the opening/closingoperation of the closure cap 16 is avoided to enable the two to bedisposed in proximity.

<Fourth Embodiment>

As shown in FIG. 4, the wick 6 of the lighter 1 of this embodiment isintegrally formed throughout of the same material. Other aspects arestructured like those of the second embodiment (FIG. 2).

The wick 6 has its flame-producing section 63 and draw-up section 64formed integrally of a porous ceramic sintered body, is retained by thewick holder 7, and has the same shape as the one in FIG. 2.

<Fifth Embodiment>

FIGS. 5(A) to (E) show various examples of the seal structure of theflame-producing section of the wick 6 by the closure cap 16.

(A) is a structure wherein a seal member 25 is disposed on the uppersurface of the top cover 4 around the wick holder 7 and seals bypressing the tip portion 16b of the closure cap 16 onto the seal member25.

(B) is a structure wherein an annular projection 4b is provided on theupper surface of the top cover 4 around the wick holder 7 while aring-like seal member 26 is attached to the sealing tip portion 16b ofthe closure cap 16, sealing being obtained by pressing the seal member26 onto the annular projection 4b.

(C) is a seal structure similar to that in FIG. 1, wherein an O-ring 27if fitted horizontally around the wick holder 7, sealing being obtainedby pressing the inner surface of the closure cap 16 onto the O-ring 27.

(D) is a structure wherein an annular seal member 28 is provided aroundthe tip of the wick holder 7, sealing being obtained by pressing the tipportion 16b of the closure cap 16 onto the annular seal member 28.

(E) is a structure wherein an annular projection 7c is provided on thetip surface of the wick holder 7 and a seal member 29 is attached to thesealing tip portion 16b of the closure cap 16, sealing being obtained bypressing the seal member 29 onto the annular projection 7c.

<Sixth Embodiment>

FIGS. 6(A) to (F) show various examples of the structure for joining orfastening the flame-producing section and the draw-up section of thewick 6 and of the structure for attaching the wick 6 to the top cover 4of the fuel tank together with the wick holder 7.

(A) is a structure wherein the flame-producing section 63 and the headof the draw-up section 62 of the wick 6 are inserted into the wickholder 7 and then joined by caulking the lower end portion (or upper endportion) of the wick holder 7, and the wick holder 7 is attached byscrewing the fastening thread 7a on the outer periphery thereof into thethreaded hole 4a provided in the top cover 4 to sandwich the O-ring 18at the bottom.

(B) is a structure similar to that indicated in the second embodiment(FIG. 2), wherein the lower end portion of the wick holder 7 is notcaulked, the lower end of the head of the draw-up section 62 is fastenedand held by the bottom portion of the threaded hole 4a of the top cover4, and the wick holder 7 is attached to the top cover 4 by fastening itfrom above to sandwich the O-ring 18 while joining the flame-producingsection 63 to the draw-up section 62.

(C) is a structure wherein the wick holder 7 is not formed with afastening thread but is attached via an anchor ring 33 by engaging anupper engaging portion 33a of the anchor ring 33 with a step portion 7dof the wick holder 7 and screwing a fastening thread 33b on the outerperiphery of the anchor ring 33 into the threaded hole 4a of the topcover 4, the fixing of the wick 6 with respect to the wick holder 7being the same as in (A).

(D) combines a structure for attaching the wick holder 7 to the topcover 4 like that of (C) and a structure for fixing the wick 6 like thatof (B).

(E) is a structure wherein a U-groove 7e is formed in the outerperiphery of the wick holder 7, an engaging projection 4e imparted withelasticity is provided on the top cover 4, and attachment is achieved byforcing the bottom portion of the wick holder 7 into the top cover 4 toengage the tip of the engaging projection 4e with the U-groove 7e, theretention of the wick 6 being the same as in (A) above.

(F) combines a structure for attaching the wick holder 7 to the topcover 4 like that of (E) and a structure for fixing of the wick 6 likethat of (B).

The liquid fuel poured into the fuel reservoir section 5 of the lighter1 or other burner is, in the case of an alcohol fuel, preferably oneusing an alcohol that is a lower monovalent alcohol, namely, methylalcohol, ethyl alcohol or propyl alcohol, as its main component andhaving added thereto one or more kinds of hydrocarbon compound havingnearly the same boiling point as the main component, namely, hexane,heptane, octane, nonane, cyclohexadiene, cycloheptene or other saturatedhydrocarbon. This is because the flame is colorless with only an alcoholfuel but the tip portion of the flame comes to be tinted lantern-yellowby the red heat of free carbon owing to the addition of the saturatedhydrocarbon. A liquid fuel composed of at least one kind among heptane,octane and nonane can also be used. An liquid fuel of a benzenehydrocarbon is also acceptable.

On the other hand, liquid fuel burners other than cigarette lightersinclude torches, lanterns and other such fire-lighting devices andlamps.

<Test 1>

A test will be described in which a lighter 1 incorporating the wick 6such as described above was used and the change in flame shape inrepeated lighting and use was measured.

In this test there was used a lighter 1 wherein the wick 6 of the firstembodiment (FIG. 1), whose tip portion 61a of the flame-producingsection 61 was fusion-bonded, was retained in a wick holder 7 with aflat tip portion. As a comparative example, there was used a lighterwherein a wick 6 such as shown in FIG. 8, whose tip of theflame-producing section 60 was not fusion-bonded, was retained in a wickholder 7 with a flat tip portion.

The operations of opening the closure caps 16 of both lighters,operating the rotating striker wheels 13 to light the wicks 6, allowingthe burning to continue for a prescribed time period and then closingthe closure caps 16 to seal the wicks 6 and extinguish the flames wererepeated, and the change in the shape of the flames H was observed.

In the comparison lighter 1, as the number of uses increased, the tip ofthe flame-producing portion 60 of the wick 6 frayed as shown in FIG. 8,the diameter of the glass fibers of the flame-producing portion 60 tipspread to 6 mm (initial diameter: 3 mm), the flame width spreadaccordingly to 12 mm (at a position 3 mm from the lower end of theflame) against a flame H shape of a flame length of 30 mm, a portion ofthe flame H touched the rotating striker wheel 13 and this portion ofthe rotating striker wheel 13 was heated and increased in temperature.

On the other hand, in the lighter according to the invention, as shownin FIG. 1, even as the number of uses increased, no change was observedin the tip shape of the flame-producing section 61 of the wick 6 or theshape of the flame H, and the flame did not touch the rotating strikerwheel 13.

Embodiments in which the shape of the wick holder for retaining the wickis modified will be shown next.

<Seventh Embodiment>

FIG. 9 shows the general sectional structure of a lighter as an exampleof a liquid fuel burner.

The basic structure of the lighter 1 is as set out above, the wick 6being installed as fixed by a wick holder 77 to pass vertically throughthe top cover 4 into the fuel tank 2. The wick 6 is formed separately ofdifferent materials at an upper flame-producing section 61 and a lowerdraw-up section 62 and the two are joined by the cylindrical wick holder77, which is made of metal and formed to have an inclined tip portion,with the lower end portion of the flame-producing section 61 and theupper end portion of the draw-up section 62 in a contacted state.

The lower end portion of the draw-up section 62 of the wick 6 contactsthe fiber material 3 in the tank 2 and draws up the liquid fuelimpregnated in the fiber material 3 utilizing capillarity. Theflame-producing section 61 of the wick 6 is lit to burn and generate aflame H.

The flame-producing section 61 is made from glass fibers by, as in FIG.1 for example, bundling glass fiber filaments and fusion-bonding the tipportion 61a to form it into a pointed shape like the tip of a writingbrush. The draw-up section 62, formed as a rod having a large-diameterhead portion 62a by molding and sintering polyethylene powder, has itshead portion 62a inserted into the lower portion of the wick holder 77and contacted with the base 61b of the flame-producing section 61 andthe lower end portion of the wick holder 77 is caulked in this state,whereby the flame-producing section 61 and the draw-up section 62 areintegrally joined to constitute the wick 6.

A closure cap 116 for evaporation prevention is provided toopenably/closably cover the flame-producing section 61 of the wick 6together with projecting portion of the wick holder 77. This closure cap116 is rotatably pivoted by a pin 17 at one end portion of the uppersurface of the top cover 4 of the tank 2. At the inner surface of theclosure cap 116 is provided an inner cover 116a for enclosing the outerperiphery of the wick holder 77 of the wick 6 and covering/sealing thewick 6. An O-ring 19 is horizontally attached to the outer peripheralroot portion of the wick holder 77 and the inner peripheral surface ofthe inner cover 116a of the closure cap 16 presses thereon to enhancethe sealing property. A face plate 48 is provided on the upper surfaceof the top cover 4.

In the lighter 1 of the foregoing structure, the tip portion 77a of thewick holder 77, which surrounds and holds the outer periphery of theflame-producing section 61 of the wick 6, is formed slantedly to differin height in the peripheral direction. The wick holder 77 is disposed sothat the portion of the inclined tip portion 77a having the highestheight is located near the rotating striker wheel 13, that is theigniter 10, and is interposed between the flame H and the rotatingstriker wheel 13.

The dimensions of the wick holder 77 are, for example, outer diameter of4 mm, inner diameter of 3 mm and inclination angle of the tip portion77a of 45°. The height of the wick 6 flame-producing section 61projecting from this wick holder 77 is 3 mm at the most exposed portion.The distance between the center of the wick 6 and the center of therotating striker wheel 13 is set at 8 mm.

In this embodiment, under conditions adjusted to make the flame length30 mm, the center of the flame H is offset relative to the center of thewick 6 by d=2 mm to the side opposite from the rotating striker wheel13, the flame width is 8 mm and the position of greatest flame width is3 mm from the lower end of the flame. With this flame shape, the flame Hdoes not touch the rotating striker wheel 13 and good burning and useconditions can be obtained even if the distance between the center ofthe wick 6 and the center of the rotating striker wheel 13 is set to anarrow 8 mm as stated above.

Although the tip portion 61a of the glass fiber flame-producing section61 of the wick 6 is fusion-bonded in this seventh embodiment, it caninstead be left as an unbonded flame-producing portion 60 as shown inFIG. 16. In this case, the tip end portion of the flame-producingportion 60 is preferably structured so as not to contact/interfere withthe open/close path of the closure cap 116.

<Eighth Embodiment>

As shown in FIG. 10, the lighter 1 of this embodiment has the same typeof wick holder 77 as in the preceding embodiment but the closure cap 120is of a different type.

In the closure cap 120 of this embodiment, one end portion of a mainbody formed in the shape of a flat plate is rotatably pivoted on the topcover 4 of the tank 2 by a pin 21, the tip portion on the opposite sidefrom the pivot portion is provided to extend along and engage with therotating striker wheel 13 of the igniter 10, and a projection 120b foropening operation is provided on the tip portion, the closure conditionbeing in an inclined state.

A cup-shaped closure portion 120a is fixed to the inner surface of themain body of the closure cap 120 to face the inclined shape of theinclined tip portion 77a of the wick holder 77. This closure portion120a is constituted so that when closed its inclination angle is thesame as the inclination angle of the wick holder 77. A seal member 22 isattached to the tip edge portion of the closure portion 120a and thisseal member 22 is structured to press onto the inclined tip portion 77aof the wick holder 77.

The flame-producing section 63 of the wick 6 in this embodiment isformed in round rod-like shape not of glass fibers but of a porous glasssintered body or porous ceramic sintered body, contains continuousbubbles (capillary passages) inside, and is formed thin at the tipportion. Its upper portion is mounted to protrude from the tip surface77a of the wick holder 77 by a prescribed amount (3 mm at the mostexposed portion). The setting of this protrusion amount, the diameterand the like determine the size of the flame. For instance, it isconstituted to have an outer diameter of 3.0 mm and a length of 10 mm.

On the other hand, the draw-up section 62 whose tip portion abuts on thelower end of the flame-producing section 63 is again a porous materialmade of a sintered body of polyethylene powder and formed into roundrod-like shape. Other aspects are formed like those of the seventhembodiment.

The closure cap 120 of this embodiment is simplified in structure andsince the closure portion 120a achieves sealing by pressing onto to theinclined tip portion 77a via the seal member 22, without fitting overthe outer periphery of the wick holder 77, the distance between thesupport position by the pin 21 of the closure cap 120 and the center ofthe wick 6 can be shortened and the distance between the wick holder 77,i.e., the wick 6, and the striker wheel 13 of the igniter 10 can befurther shortened to make the lighter 1 compact.

<Ninth Embodiment>

As shown in FIG. 11, the shape of the tip portion of the wick 6 of thelighter 1 of this embodiment is different.

The flame-producing section 63 of the wick 6 is formed in a rod-likeshape of a porous ceramic sintered body and its tip portion is removedslantedly at the side portion opposite from the support pin 17 of theclosure cap 16, whereby it is structured to avoid interference with theopening/closing rotation of the closure cap 16.

The closure cap 16 is structured to openably/closably cover theflame-producing section 63 of the wick 6 together with the projectingportion of the wick holder 77 but not to cover the top of the igniter10. A seal member 22 is attached to the tip portion of the sealingportion of the closure cap 16 and this seal member 22 is constituted toachieve sealing by pressing onto the top cover 4 around the wick holder77 at closing operation of the closure cap 16.

<Tenth Embodiment>

As shown in FIG. 12, the shapes of the tip portion of the wick 6 and thewick holder 77 of the lighter 1 of this embodiment are different.

The flame-producing section 63 of the wick 6 is formed in a rod-likeshape of a porous ceramic sintered body and the corner of its tipportion is removed slantedly at the side portion opposite from thesupport pin 17 of the closure cap 16 and, further, the tip portion 77aof the wick holder 77 is also removed of part of its highest portion,whereby they are structured to avoid interference with theopening/closing rotation of the closure cap 16. Other aspects are thesame as in the ninth embodiment.

<Eleventh Embodiment>

As shown in FIG. 13, the wick 6 of the lighter 1 of this embodiment isintegrally formed throughout of the same material. Other aspects arestructured like those of the tenth embodiment.

In other words, the wick 6 has its flame-producing section 63 anddraw-up section 64 formed integrally of a porous ceramic sintered body,is retained by the wick holder 77, and has the same shape as the one inFIG. 12.

<Twelfth Embodiment>

FIGS. 14(A) to (F) show various examples of the seal structure of theflame-producing section of the wick 6 by the closure cap 16 in alighters equipped with a wick holder 77 with an inclined tip.

(A) is a structure wherein a seal member 25 is disposed on the uppersurface of the top cover 4 around the wick holder 77 and seals bypressing the tip portion 16b of the closure cap 16 onto the seal member25.

(B) is a structure wherein an annular projection 4b is provided on theupper surface of the top cover 4 around the wick holder 77 while aring-like seal member 26 is attached to the sealing tip portion 16b ofthe closure cap 16, sealing being obtained by pressing the seal member26 onto the annular projection 4b.

(C) is a structure wherein an O-ring 27 if fitted horizontally aroundthe wick holder 77, sealing being obtained by abutting the inner surfaceof the closure cap 16 onto the O-ring 27.

(D) is a structure wherein a seal member 28 is provided slantedly on theinclined tip portion 77a of the wick holder 77, sealing being obtainedby pressing the inclined lower end portion 16c of the closure cap 16onto the annular seal member 28.

(E) is a structure wherein an annular projection 77b is provided on theinclined tip portion 77a of the wick holder 77 and a seal member 29 isattached to the inclined lower end portion 16c of the closure cap 16,sealing being obtained by pressing the seal member 29 onto the annularprojection 77b.

(F) is a structure wherein an O-ring 30 is fitted on the outer peripheryof the wick holder 77 slantedly in parallel with the inclined tipportion 77a, sealing be obtained by pressing the inner surface of theinclined lower end portion 16c of the closure cap 16 onto the O-ring 30.

<Thirteenth Embodiment>

FIGS. 15(A) to (F) show various examples of the structure for joining orfastening the flame-producing section and the draw-up section of thewick and of the structure for attaching the wick to the fuel tanktogether with the wick holder.

(A) is a structure wherein the flame-producing section 63 and the headof the draw-up section 62 of the wick 6 are inserted into the wickholder 77 and then joined by caulking the lower end portion (or upperend portion) of the wick holder 77, and the wick holder 77 is attachedby screwing a fastening thread 77c on the outer periphery thereof intothe threaded hole 4a formed in the top cover 4 to sandwich the O-ring 18at the bottom.

(B) is a structure wherein the lower end portion of the wick holder 77is not caulked, the lower end of the head of the draw-up section 62 isheld by a retaining portion 4c of the top cover 4, and the wick holder77 is attached to the top cover 4 by fastening it in the threaded hole4a from above to sandwich the O-ring 18 while joining theflame-producing section 63 to the draw-up section 62.

(C) is a structure wherein the wick holder 77 is not formed with afastening thread but is attached via an anchor ring 33 by engaging anupper engaging portion 33a of the anchor ring 33 with a step portion 77dof the wick holder 77 and screwing a fastening thread 33b on the outerperiphery of the anchor ring 33 into the threaded hole 4a of the topcover 4, the fixing of the wick 6 with respect to the wick holder 77being the same as in (A).

(D) combines a structure for attaching the wick holder 77 to the topcover 4 like that of (C) and a structure for fixing wick 6 like that of(B).

(E) is a structure wherein a U-groove 77e is formed in the outerperiphery of the wick holder 77, an engaging projection 4e imparted withelasticity is provided on the top cover 4, and attachment is achieved byforcing the bottom portion of the wick holder 77 into the top cover 4 toengage the tip of the engaging projection 4e with the U-groove 77e, theretention of the wick 6 being the same as in (A) above.

(F) combines a structure for attaching the wick holder 77 to the topcover 4 like that of (E) and a structure for fixing the wick 6 like thatof (B).

<Test 2>

Next, there will be indicated the results when a lighter was used likethat of the seventh embodiment (FIG. 9) except that the flame-producingsection of the wick incorporated therein was the one shown in FIG. 16whose tip portion is not fusion-bonded, the wick was lit and allowed toburn, and the change in the shape of the flame when a metal platesimulating an igniter was brought near the flame was obtained bymeasuring the distance between the flame and the metal plate. The shapeof the metal plate was: height of 8 mm from the lower end of the flameand width of 6 mm, 8 mm or 10 mm. Each metal plate simulated an igniter(striker wheel) and the metal plate changed the flame shape by changingthe flow of air relative to the flame.

As a comparative example, the state was measured when identical metalplates were brought near the flame of a lighter wherein the tip portionof the wick holder was of constant in height in the peripheral directionand had a horizontally flat shape, while being identical in otheraspects. FIG. 17 shows the measurement results for the invention productand FIG. 18 the measurement results for the comparative example.

In the case of FIG. 18 for the comparative example in which the tip ofthe wick holder was flat, when the distance A between the metal plateand the center of the wick was made 7 mm, the distance B between theflame and the metal plate was 2 mm at the plate widths of 6 mm and 8 mmand made contact with the flame in the case of the metal plate of 10 mmplate width. When the distance A between the metal plate and the centerof the flame was made 6.5 mm, the metal plates of all plate widthstouched the flame.

On the other hand, in the case of FIG. 17 according to the invention, inwhich the tip portion of the wick holder 77 was inclined, when thedistance A between the center of the wick and the metal plate was made 7mm, the distance B between the flame side surface and the metal platewas 4 mm for the metal plates of 8 mm and 10 mm plate width and was 5 mmfor the metal plate of 6 mm plate width, which values are greater thanin the comparative example.

The foregoing results mean that in configuring lighters, if the distancebetween the wick 6 and the igniter 10 is fixed, distance can be securedbetween the flame and the igniter by inclining the tip of the wickholder 77, whereby temperature rise of the igniter can be prevented, theigniter can be brought closer to the wick, the lighter can be madesmaller, and the reliability of its igniting performance can beenhanced.

We claim:
 1. In a liquid fuel burner comprising a wick for drawing up bythe capillarity of a draw-up section liquid fuel to be burned at aflame-producing section, an igniter for igniting the flame-producingsection of the wick and a closure cap for preventing evaporation capableof sealing the flame-producing section of the wick openably andclosably, a wick of the liquid fuel burner characterized in that theflame-producing section of the wick is constituted in a shape to have atapered tip portion.
 2. A liquid fuel burner according to claim 1,characterized in that the closure cap is constituted to open and closeabout a pivot at one end portion thereof and the tip portion of theflame-producing section on a side opposite from the pivot of the closurecap is removed.
 3. A liquid fuel burner according to claim 1,characterized in that in the wick a tip portion of the flame-producingsection made of glass fibers is fusion-bonded into a pointed shape likethe tip of a writing brush.
 4. A liquid fuel burner according to claim3, characterized in that the wick is shaped by bundling glass fibers,heating and fusing a portion thereof with a high-temperature burner anddrawing out and separating the fused portion.
 5. A liquid fuel burneraccording to claim 1, characterized in that the wick comprises aflame-producing section composed of a porous glass material havingcontinuous bubbles or a sintered porous ceramic material and constitutedin a tapered shape.
 6. A liquid fuel burner according to claim 1,characterized in that the wick is formed of different materials at thedraw-up section and the flame-producing section.
 7. A liquid fuel burneraccording to claim 1, characterized in that the draw-up section and theflame-producing section of the wick are formed integrally of the samematerial.
 8. In a liquid fuel burner comprising a wick for drawing up bythe capillarity of a draw-up section liquid fuel to be burned at aflame-producing section, an igniter for igniting the flame-producingsection of the wick and a closure cap for preventing evaporation capableof sealing the flame-producing section of the wick openably andclosably,the liquid fuel burner characterized in that a wick holder forholding the wick is provided around the flame-producing section at a tipof the wick and a tip portion of the wick holder is formed to differ inheight in a circumferential direction, a tip portion of high heightbeing disposed to be interposed between the flame-producing section ofthe wick and the igniter.
 9. A liquid fuel burner according to claim 8,characterized in that the closure cap is constituted to open and closeabout a pivot at one end portion thereof and an edge portion of asealing portion thereof for sealing the flame-producing section of thewick is formed to differ in height in a circumferential directioncomplementarily to the shape of the tip portion of the wick holder. 10.A liquid fuel burner according to claim 8, characterized in that in thewick a tip portion of the flame-producing section on the side oppositefrom the pivot of the closure cap is removed.
 11. A liquid fuel burneraccording to claim 8, characterized in that in the wick a tip portion ofthe flame-producing section made of glass fibers is fusion-bonded into apointed shape like the tip of a writing brush.
 12. A liquid fuel burneraccording to claim 8, characterized in that the wick is composed of aporous glass material having continuous bubbles or a sintered porousceramic material.
 13. A wick of a liquid fuel burner according to claim8, characterized in that the wick is formed of different materials atthe draw-up section and the flame-producing section.
 14. A wick of aliquid fuel burner according to claim 8, characterized in that thedraw-up section and the flame-producing section of the wick are formedintegrally of the same material.